The complete or partial detachment of ligaments, tendons, and/or other soft tissues from their associated bones within the body are relatively commonplace injuries, particularly among athletes. Such injuries are generally the result of excessive stresses being placed on these tissues. By way of example, tissue detachment may occur as the result of an accident such as a fall, over exertion during a work-related activity, during the course of an athletic event, or in any one of many other situations and/or activities.
In the case of a partial detachment, the injury will frequently heal itself, if given sufficient time and if care is taken not to expose the injury to further undue stress. In the case of complete detachment, however, surgery may be needed to re-attach the soft tissue to its associated bone or bones. Numerous devices are currently available to re-attach soft tissue to bone. Examples of such currently-available devices include screws, staples, suture anchors, and tacks. In soft tissue re-attachment procedures utilizing screws, the detached soft tissue is typically moved back into its original position over the bone. The screw is then screwed through the soft tissue and into the bone, with the shank and head of the screw holding the soft tissue to the bone. Similarly, in soft tissue re-attachment procedures utilizing staples, the detached soft tissue is typically moved back into its original position over the bone. The staple is then driven through the soft tissue and into the bone, with the legs and bridge of the staple holding the soft tissue to the bone.
In soft tissue re-attachment procedures utilizing suture anchors, an anchor-receiving hole is generally first drilled in the bone at the desired point of tissue re-attachment. A suture anchor is then deployed in the hole using an appropriate installation tool. This effectively locks the suture , with soft tissue attached thereto.
While current suture anchors are effective in anchoring soft tissue to bone, one drawback with current devices is that the suture and soft tissue attached thereto can slip or otherwise move while the suture anchor is being driven into the bone. Once the suture anchor has been driven into bone, the suture and the soft tissue cannot be adjusted to adjust the position of the soft tissue relative to the bone because the driven suture anchor holds the suture and soft tissue in place. The soft tissue may therefore not be in an optimal position to facilitate healing.
Even if the suture and the soft tissue can be adjusted after the suture anchor has been driven into bone, tying the suture into a knot to secure the soft tissue in place relative to the bone can cause the soft tissue to slip from an optimal position. More particularly, surgeons typically tie suture ends using a surgical sliding knot such as the Tennessee Slider or Duncan Loop. After advancing the knot distally to tighten the loop, a number of additional half hitches or other knots are tied in an effort to secure the new location of the sliding knot. The additional knots are needed because a conventional sliding knot used in current repair constructs does not provide the necessary protection against loosening or slippage, especially when tension is placed primarily on the limbs of the loop. The generally accepted practice is to follow the sliding knot with at least three reversed half hitches on alternating posts of the suture. Before one or more half hitches or other knots can be added to the sliding knot, however, there exists a potential for the sliding knot to slip, that is, for the loop to enlarge as the tissue places tension on the loop. This has been referred to as “loop security” and can reportedly occur even in the hands of very experienced surgeons. Sometimes, even fully-tied knots may slip. In addition to this “loop security” problem, conventional knots can have an overall size that can be obstructive or intrusive, especially in tight joints, which may damage cartilage or other tissue by abrasion with the knot.
Accordingly, there remains a need for improved methods and devices for securing soft tissue to bone.